How does music tastes differ from country to county?

Rhythm, Religion and Rhyme.
The three Rs.   The universal language of music has many dialects that differ infinitely in these three fundamental ways. 

Music varies by region. Here in Seattle and the PNW in general its all Gospel music. Well except for Portland, where its all 80's. 1880's. Los Angeles is heavily classical, except the hip hop community inexplicably goes almost entirely small ensemble chamber music. Down South of course it is and always has been disco. All through Montana and well into the Dakotas it is hard to get anything but death metal on the radio. 

I thought its a very good question, nevermind the irony of previous member. Perhaps the best answer would be to look record sales or musical programs in places you have interest.
But, imho, its the corporate media that dictates the taste of popular music (not only music) among younger population.
As for the rest, I guess I could say and not be wrong that (talking about Europe) is that states that have invested more in broader cultural education (that does not relate always with the average gdp) of their citizens have in general 'better taste' in music or in culture in general.
Than again, I would say also that genral trend is dumbing down, but cinics will say that that was always the case